Optical excitation of surface plasmons the surface plasmon. This gives substantial potential for [7 Schroder, U. 1981, Surf, Sci, 102, 118. the study of strong optical field effects[28 as well as [8] Innes, R. A and Sambles, J.R. 1987, J. Phys. F: Metal P strong non-linear effects due to local heating[ 29, 30]. One 17,277 of the most striking experiments in this area is that by 9) Lawrence C: 1991, Private communication Nunzi and Ricard[31] who studied optical phase [11) Chandezon, J, Dupuis, M. T, Cornet, G, and Maystre. D. 1982. conjugation through pulsed laser excitation of thermal J. opt. Soc. Amer., 72, 839 gratings in silver films. It would appear there is much [12] Bryan-Brown, G. P. Sambles, J.R., and Hutley. M. C, 1990, J more work to be undertaken in this area, particularly mod. Optics, 37, 1227. with non-centrosymmetric overlayers [13] Pockrand, L. 1978. Surf. Sci, 72, 577. Finally we would like to highlight just one area of [14] Kovacs, G.J.1978. Surf. Sci. 78, L245 [15] Dumas, P, Dubarry-Barbe, J. P. Riviere. D, Levy, Y, and study where surface plasmon excitation is uniquely Corset, J. 1983. de phys. 44 C10-205 aluable. Recently Lajendijk and co-workers[32, 33] [16] Brown, C.A. Burns, F C, Knoll, W. Swalen, J D and Fischer have used pulsed excitation of surface plasmons to probe A.1983.Jpys.Chem,87,3616 the dynamics of thin metal films. With some superb 17] Puderbach, S, Herminghaus, S, and Leiderer, P, 1988, Phys et,A.130.401 experimental techniques they have been able to examine [18 Pollard, J D, and Sambles, J.R 1987, Optics Comnun, 64, 529 electron relaxation rates as well as phonon decay times. [191 Sambles, J. R Pollard, J D, and Bradberry, G Thus while there is much interest in the use of optical Optics, 37, 841 excitation of surface plasmons in devices it is also [20] Nylander, C, Liedberg, B, and Lind, T, 1982, Sensors and beginning to find a use in more fundamental physics, an Actuators. 3. 79 area which we hope to see expand [211 Fontana. E, Pantell, R. H, and Strober, S, 1990. App/. Optics 29,4694. The authors acknowledge the support of SERC and [22] Tadjeddine, A. Abraham, M.and Hadjadi, A,1986,J the University of Exeter for this work and thank Dr S electroanal. Chen, 204. 229 Elston, Mr G Bryan-Brown and Mr P Vukusic for [23] Welford, K.R., and Sambles, J. R 1987, App. Phys. Lett., 50, 871 providing the experimental data used to produce figures [24] Elston, S J, and Sambles,J.R,1989,Appl.Phys.Lett.55,1621 8,9,1land12. [25] Tassin, J. F, Siemens, K. L, Tang, W. T, Hadziioannou, G Swalen, J. D, and Smith, B. A. 1989. J. phys. Chen, 93, 2106 26 Johnston, W, Stewart, G, Culshaw, B. and Hart, T, 1988 ctron. Left, 24, 866. References [27] Yeatman, E, M, and Ash, E.A. 1988, SPIE Scanning Microscopy [I Lynch, D W, and Hunter, w R, 1985, in Handbook of Optical [28] Schmidlin, E M and Simon.H. 00 J., 1988. Applied Optics, 28, 3323. Constants of Solids edited by E. D. Allik,(Ac ademic Press). [29] Martinot, P, Laval,, S, and Koster, A, 1984. J de Phys., 45, 597. [30] Innes, R A. and Sambles, J. R, 1989, J. Phys: Condensed Matter. [2 Smith, D. Y Stiles, E, and Inokuti, M, 1985. ibid. 369 1.6231 [3]otto,A.1968.Z.Phys,216.398. [31] Nunzi, J M, and Ricard. D, 1984, Appl. Phys [4 Tillin. M. D, and Sambles, J. R 1988, Thin solid Filns, 167, 73. 32 van Exter, M, and Lagendijk, A. 1988, Phys [5 Tillin, M. D. and Sambles, J.R., 1989. Thin solid Films, 172, 27 33 Grooneveld, R. H. M. Sprik. R, and Lagendijk, A 6] Kretschmann, E, and Raether, H, 1968, Z. Naturf A, 23, 2135 Rev. Lett., 64. 784 Roy Sambles obtained his PhD in electron microscopy from n 1970. In 1972 he moved to a he Physics Department at Exeter where team of 20 studying the physics lin films. He has sat on ber of serc co been appointed to a personal Professorship in Experimental Physics Geoff Bradberry obtained his PhD in semiconductor physics from the University of Leicester in 1964 and was appointed lecturer in Department of Physics at Exeter in 1966. Subsequently his research covered various topics in solid state physics. Recently he has worked on Brillouin scattering in liquid crystals and the optical excitation of surface plasmons and other guided modes. Fuzi Yang obtained his batchelors degree from Qinghua University in Beijing in 1968. In 1981 he was appointed Professor in the Applied Physics Department of Jiaotong University. Since November 1988 he has been a visiting researcher at the Department of Physics at Exeter. Recently he has been awarded a PhD by the University. At present he is studying the optics of thin liquid crystal layers